Many of today's consumer electronics products include the provision of a battery power source. Some devices, such as cellular telephones, pagers, portable entertainment devices, and hand held toys, are totally dependent upon battery power to operate. Other devices, such as televisions, radios, alarm clocks, computers and telephones, are often connected to art external AC power source for general operation, but utilize a battery power source to perform backup functions and/or to retain programmed data stored in the device's memory upon a temporary loss of external electrical power. For example, television channel programming information is retained during a power outage; a clock radio continues to keep time in the event of a power outage so that the clock does not have to be reset upon restoration of power; and stored telephone numbers and user established functions are retained in a telephone in the event of a power outage.
Whether the battery or batteries in the electronic device serves as the primary or a secondary power source, the electronics product designer is necessarily concerned with several factors relating to the provision of battery power. First, after determining the level of power required to power the circuit or circuits of the device, the electrical designer decides on the number and type of batteries necessary to support the device's circuit(s). In some devices, such as hearing aids or watches, a single, small and simple button battery is all that is required and all that can be utilized due to physical constraints. In other devices, such as a portable stereo system, several batteries of larger dimension are required to provide sufficient power to the device. It is therefore desired to provide a battery compartment design that can be configured for use in a variety of different electrical devices and for varying numbers and sizes of batteries.
Another concern of the designer centers around the physical constraints imposed by the preferred size and shape of the device. The location of the batteries must permit easy access by the purchaser to change weakened or dead batteries, while not leading to inadvertent disconnection during operation. Also, an aesthetically pleasing product must result. In particular, the battery compartment housing the batteries should not detract from the overall appearance of the device, nor dictate the external appearance of the device, unless the device itself is very small. Further, it is desirable for the batteries to be positioned in such a way as to occupy a minimal amount of surface area of the device's printed circuit board (PCB). In many devices, physical size constraints result in making the surface area of the PCB at a premium and as much area as possible is needed to support the device's numerous capabilities and functions. Under such constraints, it is therefore undesirable to lay the batteries across the PCB.
When one or more cylindrically shaped batteries are required to power the device, a common design involves the provision of a compartment into which the batteries are stacked. Consider, for example, a full-size flashlight requiring two or more batteries to operate. The handle of the flashlight often accommodates a stack of batteries. Not only may such stacking be impractical due to physical constraints, stacking makes it very difficult for the consumer to ascertain in what orientation the batteries are to be installed in the battery compartment. Therefore, it is desirable to provide a battery compartment which does not require stacking of the batteries.
Even when batteries are not stacked, access to the battery compartment is often provided in a difficult to reach position. Further, when the consumer places batteries into the compartment, it is often difficult to ascertain the proper orientation of the batteries in the compartment. Therefore, it is desired to provide easy access to the battery compartment and to provide orientation information to facilitate proper battery placement by the consumer.
Another common battery compartment design involves the use of a recess formed in the bottom or underside portion of the device housing and the placement of a removable access door over the recess. A few of the shortcomings associated with this design are the inconvenience of the location of the recess (requiring the device to be lifted in order to access the compartment), the awkwardness of removing and replacing the door, and the risk that the door itself will be lost or broken when removed from the housing. Therefore, it is desirable to provide a battery compartment that is positioned on a portion of the device's housing that is easy to access, which is easy to open and close, and which does not include removable parts which may be lost or broken when removed.
Some devices, such as hearing aids, attempt to overcome one or more of these shortcomings through the use of a pivotable compartment for retention of the battery in the device. Pivotable battery compartments are disclosed in U.S. Pat. Nos. 5,413,499, 5,404,407, 5,386,476, for example. A drawback associated with pivotable compartments is that the battery is automatically electrically disconnected from the device circuitry when the compartment is pivoted to the open position. Such electrical disconnection causes loss of memory and/or functionality during inspection of the batteries. Similar disconnection of the batteries occurs with devices having battery drawers, such as is disclosed in U.S. Pat. Nos. 5,280,273 and 5,113,183. Devices having battery packs, such as that of U.S. Pat. Nos. 5,410,141 and 5,023,824, for example, are also disconnected from the device's circuitry when the battery pack is removed from the battery pack compartment. It is therefore desirable to provide a compartment in which the battery(ies) held by the compartment may be inspected, as for determining the strength of the battery, without disconnecting the battery from the device's circuitry. In this manner, if the battery(ies) are used to retain functions or data in memory, those functions or data will not be lost by inspection of the battery(ies) in the compartment.
In resolving the above-stated shortcomings and disadvantages of the prior art, cost containment must also be a consideration for a battery compartment. The compartment should be comprised of few inexpensive parts and be easy to assembly, thereby minimizing the costs associated with manufacture of the battery compartment.